"If we are in a position of increased outbreaks, low immunisation is even more worrying," he said.

Dr Brown added: "Vaccination is one of the few miracles of modern medicine. It is one of the safest and most cost-effective methods we have to prevent the spread of disease."

The Royal College's immunisation expert Dr David Elliman said that a lack of awareness around the importance of getting both jabs, rather than a decision by the parents, could be causing children to miss the second dose.

Dr Elliman said: "The best solution is GPs sending regular reminders to parents, and all GPs should make sure they have an efficient reminder system in place."

He added that anyone who has missed the MMR vaccine can still get it for free at their GP.

"But even healthy children can get nasty measles and die from it," he added. "A third of measles cases will end up in the hospital."

Public Health England said that they are working closely with the NHS and general practice staff to improve uptake.

PHE's Dr Michael Edelstein said: "We are seeing small reductions in uptake for most of the childhood vaccines, which is why we continue to encourage all parents to get the best protection for their children by ensuring they are fully immunised."

The British Society for Immunology is calling on the Government and the NHS to conduct a review of immunisation rates, to learn from the areas that are doing well and apply that to the rest of the country.